Protests are being held across Spain after five men accused of the gang rape of a teenager during the running of the bulls festival in Pamplona were found guilty of the lesser offence of sexual abuse.

The attack two years ago prompted a national outcry, as did the subsequent trial, which was widely criticised as a cross-examination of the 18-year-old woman rather than the men who attacked her.

The verdicts were delivered at a court in Pamplona, the capital of the Navarre region of northern Spain. José Ángel Prenda, Alfonso Cabezuelo, Antonio Manuel Guerrero, Jesús Escudero and Ángel Boza were sentenced to nine years’ imprisonment, five years’ probation and ordered to pay €10,000 each to the woman. Guerrero, a Guardia Civil police officer, was also fined €900 for stealing her phone after the attack.

Protesters in Pamplona shouted “This justice is bullshit!”, “It’s not abuse, it’s rape!” and “If they touch one of us, they touch all of us!” after the verdict was read out. On Thursday evening thousands more demonstrators gathered outside the justice ministry in Madrid, the Plaça Sant Jaume in Barcelona and in cities across the country.

The men were found guilty of the “continuous sexual abuse” of the woman in the lobby of a building in the early hours of 7 July 2016, but not of rape.

Under Spanish law, the lesser offence of sexual abuse differs from rape in that it does not involve violence or intimidation. One of the judges argued that the men should have been cleared of all charges except the phone theft.

The men, who called themselves la manada or “the wolf pack” in their WhatsApp group, had offered to walk the woman to her car but instead took her into the hall of a building, attacked her and filmed the assault on their phones.

The victim was later found crying on a bench. She described her attackers to police, who arrested the five men the following day.

Their defence lawyers claimed the woman had consented and had let one of the men kiss her. They also argued that 96 seconds of video footage from the men’s phones – showing the woman immobile and with her eyes shut during the attack – was proof of consent.

The prosecution, however, said the victim had been too terrified to move.

“The defendants want us to believe that on that night they met an 18-year-old girl, living a normal life, who, after 20 minutes of conversation with people she didn’t know, agreed to group sex involving every type of penetration, sometimes simultaneously, without using a condom,” the prosecutor Elena Sarasate said.

If the sex was consensual why had they taken her phone, Sarasate asked. “The obvious thing would be to exchange phone numbers, not steal her phone.”

The proceedings were also criticised after the judges accepted into evidence a report compiled by a private detective hired by some of the defendants. The detective had followed the woman over several days and produced photographs of her smiling with friends.

This was presented as evidence that she had not suffered any lasting trauma, prompting hundreds of women to demonstrate outside court holding signs reading: “We believe you, sister.”

Thursday’s verdict came after five months of deliberation by judges. Prosecutors had sought jail terms of 22 years each.

The woman’s lawyer said she was disappointed with the sentence and would appeal against it. A spokeswoman for the Navarre regional government said it did not agree with the verdict and would also appeal.

A lawyer for four of the men said they planned to appeal against their sentences, saying the court “can’t just come up with the offence of sexual abuse when it never formed the basis of the accusation and wasn’t something the defence could prepare for”.

The verdicts were quickly and fiercely criticised by many senior politicians and human rights groups.

Susana Díaz, the president of the regional government of Andalusia, tweeted: “I always respect judicial sentences but this is one I neither understand nor agree with. We must have zero tolerance for sexual violence throughout society.”

Her colleague, Pedro Sánchez, the leader of Spain’s socialist party, wrote: “She said NO. We believe you and we’ll keep believing you. If what the ‘wolfpack’ did wasn’t group violence against a defenceless woman, then what do we understand by rape?”

As demonstrations were announced across Spain, Amnesty International said: “The lack of legal recognition that sexual relations without consent constitute rape gives rise to the idea that it’s down to us as women to protect ourselves from rape.

Meanwhile the international human rights group Women’s Link said the case had offered judges a “unique opportunity” to set a precedent that would help protect victims of sexual assaults. But “the court didn’t take it. Once again. Once again, what a disappointment.”

Spain’s deputy prime minister, Soraya Sáenz de Santamaría, said while the judge’s sentences ought to be respected, the authorities now needed to analyse what had happened “to avoid such behaviour happening again in this country”.

In a tweet posted shortly after the verdicts were read out, Spain’s national police force wrote “No means no” 12 times, along with their emergency phone number and the message: “We’re with you.”